SEN12VTS: Sentinel 1 and 2 Vegetation Time-Series Dataset

Overview

The SEN12VTS (Sentinel-1 & Sentinel-2 Vegetation Time-Series) dataset has been created to support research on time-series analysis for vegetation indices, specifically targeting NDVI (Normalized Difference Vegetation Index) regression tasks. Recognizing the lack of datasets catering to this specific temporal and spatial need, SEN12VTS was developed to fill the gap with a high-quality, Europe-focused time-series dataset.

Motivation

This dataset is part of the GUARDIANS project, aiming to build models for vegetation monitoring across Europe. The focus is on:

• Highly vegetated areas.
• Sampling over time to enable the reconstruction of coherent time-series for selected zones.

Dataset Description

Spatial and Temporal Extent

• Region: Europe (approx. bounded by EPSG:4326 (-10.5, 34.5, 31.6, 71.5)).
• Temporal Coverage: 2022–2023.
• Spatial Resolution: 10 meters.

Data Sources

1. ESA WorldCover 2021: Used to identify highly vegetated areas.
2. Sentinel-1 RTC: Radiometrically Terrain Corrected radar imagery for ascending and descending orbits, VV and VH polarization.
3. Sentinel-2 L2A: Atmospherically corrected optical imagery with 12 spectral bands and Scene Classification (SCL).

Sampling Methodology

• Bounding boxes (bboxes) of size 512x512 pixels were sampled where 90% of pixels corresponded to vegetation categories (WorldCover values: 10, 20, 30, 40, 90, 95).
• Non-overlapping bboxes were selected within the Europe bounds.
• Sentinel-1 and Sentinel-2 data were downloaded for 1,166 bboxes across the two years.
• Final cropped tiles: 256x256 pixels.

Dataset Statistics

• BBoxes (2022 only): 36
• BBoxes (2023 only): 454
• BBoxes (both years): 676
• Total Dataset Size: ~824.89 GB

Data Structure

Each bbox folder contains the following subfolders and files:

bbox_number/
    ├── s1_rtc/
    │   ├── ascending/
    │   │   ├── s1_rtc_YYYYMMDDTHHMMSS.tif
    │   │   ├── s1_rtc_YYYYMMDDTHHMMSS.tif
    │   │   ├── ...
    │   ├── descending/
    │       ├── s1_rtc_YYYYMMDDTHHMMSS.tif
    │       ├── s1_rtc_YYYYMMDDTHHMMSS.tif
    │       ├── ...
    ├── s2/
    │   ├── s2_YYYYMMDDTHHMMSS.tif
    │   ├── s2_YYYYMMDDTHHMMSS.tif
    │   ├── ...
    ├── worldcover/
        ├── worldcover.tif

File Formats

• TIFF (Tagged Image File Format): Used for storing all raster data with metadata and lossless compression.

Sentinel Data Details

Sentinel-1 RTC

• Pre-processed for radiometric terrain correction and orthorectified to UTM zones.
• Data stored in ascending and descending orbits to allow analysis of orbit-specific effects.
• Each file has two bands, in this order: VV, VH

Sentinel-2 L2A

• 12 spectral bands selected, along with a scene classification map (SCL).
• Resolutions vary from 10m to 60m (resampled to 10m).

WorldCover

• Extracted and resampled to match bbox projections for consistency.

Example Visualization

The dataset provides:

• RGB composites from Sentinel-2 (red, green, and blue bands).
• NDVI derived from Sentinel-2 data.
• Sentinel-1 radar images for both polarizations (ascending and descending).
• WorldCover classification maps.

Citation

If you use SEN12VTS in your research, please cite this repository and the corresponding publication.

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Usage

The dataset can be used for various applications, including but not limited to:

• NDVI regression.
• Vegetation monitoring and analysis.
• Time-series forecasting.
• Multi-sensor data fusion.

Licensing

The dataset is distributed under MIT license, and its use is subject to compliance with the Sentinel and ESA WorldCover data usage policies.

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Contact

For questions, issues, or contributions, please open an issue on this repository or contact [email protected].